ENERGY EFFICIENT STORAGE By

Er.V.Vallivel, M.E Assistant Executive Engineer/ MRT/ TNEB/

MuppandalRENEWABLE ENERGY SOURCES-TAMIL NADU/ INDIA.

What is Energy Storage?» The concept

• Energy storage devices are “charged” when these absorb

energy, either directly from renewable generation devices or

indirectly from the electricity grid.

• “discharge” happens when delivering the stored energy back

into the grid.

• Charge and discharge normally require power conversion devices,

to transform electrical energy (AC or DC) into a different

form of electrical, thermal, mechanical or chemical energy.

Energy Storage

• Renewable energy is often intermittent (like wind and sun), and storage allows use at a convenient time(Un-firm Energy Generation)

• Compressed air, flywheels, weight-shifting (pumped water storage) are developing technologies

• Batteries are traditional for small systems and electric vehicles; grid storage is a financial alternative

• Energy may be stored financially as credits in the electrical “grid”

Need for Energy Storage

It is inevitable!!!

• Mode of operation in grid.• Excessive generation.• Demand response.• Transmission constraints.• Effects of operation due to High Freq. in grid.• Reducing Transmission projects.• Development of renewable energy sources.

Types of Energy to be stored

• Energy generated by Hydro-power stations during High frequency/lower demand operations.

• Energy generated by Renewable power sources during High frequency/lower demand operations.

• Tapping of the Natural resources blended in environmental.

• To increase or to develop the green power generation in turn to reduce Global carbon deposit level.

Energy Storage Technologies

• Mechanical Compressed air energy storage (CAES) Pumped hydroelectric storage Flywheels• Electrical Ultra Capacitors• Chemical Hydrogen storage• Electro chemical

Batteries

Present scenario in India done by hydro electric power station

• 2,600 MW total capacity are working as pumped storage from Hydro electric power stations.

• In TamilNadu, TNEB has 1 plant at Kadamparai having 4 units of 100MW each is working well at the grid frequency 49.2 hertz.

Renewable Energy sourcesIntegration of Renewable Energy with

Grid

Installed capacity (MW)-RES 1985-2013 in India

0 18 32 902 1,628

7,761

2450427542

0

5,000

10,000

15,000

20,000

25,000

30,000

1985 1990 1992 1997 2002 2007 2012 2013Data Source: CEA Website

Concentration of RES in certain States

TAMILNADU Generation Mix (As on 31.07.2013)

Impact of higher growth of RES in TamilNadu Grid

• Out of total generating capacity RES contribute more than 40%.

• This is non conventional.• Forced Back down of RES due to high freq

happens.• 10% of energy storage is possible.• In Rainy days, low load demand period, 100%

RES is likely to be shut down.

Advantages of Energy Storage

• Supporting the Grid during the critical condition.• Transmission loss minimizing.• Availability of supply when absence of grid.• Captive generation possible at the instant of grid

failure.• Reduce generation cost.• Adapting the green power making the global

evergreen.

19 MW solar park in Germany

The 19.9 MW Gemasolar solar plant in Spain features 15 hours of storage and can supply power 24 hours a day

Gemasolar

The plant is a 140 m high solar power tower, using molten salt as its heat transfer fluid and energy storage medium.

Gemasolar is the first commercial solar plant with central tower receiver and molten salt heat storage technology. It consists of a 185 ha solar field that has a 140-m high tower receiver, a power island and 2650 heliostats, each 120 m2 and distributed in concentric rings around the tower.

The most innovative aspects of the plant, are its molten salt receiver, its heliostats aiming system and its control system. In addition, its storage system allows it to produce electricity for 15 hours without sunlight (at night or on cloudy days).

Gemasolar

This storage capacity makes its solar power manageable so that it can be supplied based on demand. The plant has already been able to supply a full day of uninterrupted power supply to the grid, using thermal transfer technology

Gemasolar, with its 19.9 MW of power, can supply 110 GWh per year — enough to supply power to 27,500 homes. The plant has been operational since May 2011.

ConclusionEnergy Storage will provide essential services along the

wholeenergy chain

• Balancing demand & supply

• Managing Transmission & Distribution grids

• Promoting demand side management

• Contributing to competitive & secure electricity

supply

Thank you… Go Green use Renewable Energy Email: valliveltneb@gmail.com